Phaeochromocytoma combined with subclinical Cushing's syndrome and pituitary microadenoma

Abstract

Objectives: Phaeochromocytoma (PHEO) occasionally associates with pathological lesions of the adrenal cortex. The coexistence of PHEO and pre-clinical Cushing's syndrome (PCS) of the same adrenal gland has rarely been reported. We report a case of PHEO and PCS originating from the same adrenal gland and discuss the peculiar diagnostic aspects of this entity. Clinical Presentation: A 64 yr old man was hospitalized to evaluate the right adrenal mass which was discovered incidentally by ultrasonography. He had a history of type 2 diabetes mellitus and hyperlipidemia. Blood pressure measurements were all normal during his hospital stay. Laboratory examination showed: urinary catecholamines were markedly increased. HbA1C of 14.3 %, midnight cortisol of 11(μg/dL), cortisol was not suppressed after the overnight 1 mg oral dexamethasone suppression test (DST): 3.42(μg/dL), 24 hr free cortisol in the urine : 213 g/day (10-100), cortisol levels were suppressed more than 50% with 8 mg of dexamethasone. CT scan of the adrenal glands showed a 6 cm well encapsulated right adrenal mass together with a clearly normal left adrenal gland. MRI investigation of the sella turcica revealed a pituitary microadenoma on the right side of the adenohypophysis He was treated with α and subsequent β blockers after the diagnosis of PHEO and PCS was made. Right adrenalectomy was performed. The pathology showed typical PHEO with adrenocortical hyperplasia. VMA, metanefrin and free cortisol levels were normalized one month after surgery. Conclusion: The present report is a rare case of PHEO combined with PCS in the same adrenal gland. © 2008 CIM.